Drivers that offload bridges need to iterate over the ports that are
members of a given bridge, for example to rebuild per-port forwarding
bitmaps when membership changes. Currently drivers typically open-code
this by combining dsa_switch_for_each_user_port() with a
dsa_port_offloads_bridge_dev() check, or cache bridge membership
within the driver.
Add dsa_switch_for_each_bridge_member() macro to express this pattern
directly, and use it for the existing dsa_bridge_ports() inline
helper.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/e7136aaa26773f39e805a00fe4ecf13cd2b83fc0.1775049897.git.daniel@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
David Yang is saying that struct flow_action_entry in
include/net/flow_offload.h has gained new fields and DSA's struct
dsa_mall_policer_tc_entry, derived from that, isn't keeping up.
This structure is passed to drivers and they are completely oblivious to
the values of fields they don't see.
This has happened before, and almost always the solution was to make the
DSA layer thinner and use the upstream data structures. Here, the reason
why we didn't do that is because struct flow_action_entry :: police is
an anonymous structure.
That is easily enough fixable, just name those fields "struct
flow_action_police" and reference them from DSA.
Make the according transformations to the two users (sja1105 and felix):
"rate_bytes_per_sec" -> "rate_bytes_ps".
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Co-developed-by: David Yang <mmyangfl@gmail.com>
Signed-off-by: David Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260206075427.44733-1-mmyangfl@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Problem description
-------------------
DSA has a mumbo-jumbo of reference handling of the conduit net device
and its kobject which, sadly, is just wrong and doesn't make sense.
There are two distinct problems.
1. The OF path, which uses of_find_net_device_by_node(), never releases
the elevated refcount on the conduit's kobject. Nominally, the OF and
non-OF paths should result in objects having identical reference
counts taken, and it is already suspicious that
dsa_dev_to_net_device() has a put_device() call which is missing in
dsa_port_parse_of(), but we can actually even verify that an issue
exists. With CONFIG_DEBUG_KOBJECT_RELEASE=y, if we run this command
"before" and "after" applying this patch:
(unbind the conduit driver for net device eno2)
echo 0000:00:00.2 > /sys/bus/pci/drivers/fsl_enetc/unbind
we see these lines in the output diff which appear only with the patch
applied:
kobject: 'eno2' (ffff002009a3a6b8): kobject_release, parent 0000000000000000 (delayed 1000)
kobject: '109' (ffff0020099d59a0): kobject_release, parent 0000000000000000 (delayed 1000)
2. After we find the conduit interface one way (OF) or another (non-OF),
it can get unregistered at any time, and DSA remains with a long-lived,
but in this case stale, cpu_dp->conduit pointer. Holding the net
device's underlying kobject isn't actually of much help, it just
prevents it from being freed (but we never need that kobject
directly). What helps us to prevent the net device from being
unregistered is the parallel netdev reference mechanism (dev_hold()
and dev_put()).
Actually we actually use that netdev tracker mechanism implicitly on
user ports since commit 2f1e8ea726 ("net: dsa: link interfaces with
the DSA master to get rid of lockdep warnings"), via netdev_upper_dev_link().
But time still passes at DSA switch probe time between the initial
of_find_net_device_by_node() code and the user port creation time, time
during which the conduit could unregister itself and DSA wouldn't know
about it.
So we have to run of_find_net_device_by_node() under rtnl_lock() to
prevent that from happening, and release the lock only with the netdev
tracker having acquired the reference.
Do we need to keep the reference until dsa_unregister_switch() /
dsa_switch_shutdown()?
1: Maybe yes. A switch device will still be registered even if all user
ports failed to probe, see commit 86f8b1c01a ("net: dsa: Do not
make user port errors fatal"), and the cpu_dp->conduit pointers
remain valid. I haven't audited all call paths to see whether they
will actually use the conduit in lack of any user port, but if they
do, it seems safer to not rely on user ports for that reference.
2. Definitely yes. We support changing the conduit which a user port is
associated to, and we can get into a situation where we've moved all
user ports away from a conduit, thus no longer hold any reference to
it via the net device tracker. But we shouldn't let it go nonetheless
- see the next change in relation to dsa_tree_find_first_conduit()
and LAG conduits which disappear.
We have to be prepared to return to the physical conduit, so the CPU
port must explicitly keep another reference to it. This is also to
say: the user ports and their CPU ports may not always keep a
reference to the same conduit net device, and both are needed.
As for the conduit's kobject for the /sys/class/net/ entry, we don't
care about it, we can release it as soon as we hold the net device
object itself.
History and blame attribution
-----------------------------
The code has been refactored so many times, it is very difficult to
follow and properly attribute a blame, but I'll try to make a short
history which I hope to be correct.
We have two distinct probing paths:
- one for OF, introduced in 2016 in commit 83c0afaec7 ("net: dsa: Add
new binding implementation")
- one for non-OF, introduced in 2017 in commit 71e0bbde0d ("net: dsa:
Add support for platform data")
These are both complete rewrites of the original probing paths (which
used struct dsa_switch_driver and other weird stuff, instead of regular
devices on their respective buses for register access, like MDIO, SPI,
I2C etc):
- one for OF, introduced in 2013 in commit 5e95329b70 ("dsa: add
device tree bindings to register DSA switches")
- one for non-OF, introduced in 2008 in commit 91da11f870 ("net:
Distributed Switch Architecture protocol support")
except for tiny bits and pieces like dsa_dev_to_net_device() which were
seemingly carried over since the original commit, and used to this day.
The point is that the original probing paths received a fix in 2015 in
the form of commit 679fb46c57 ("net: dsa: Add missing master netdev
dev_put() calls"), but the fix never made it into the "new" (dsa2)
probing paths that can still be traced to today, and the fixed probing
path was later deleted in 2019 in commit 93e86b3bc8 ("net: dsa: Remove
legacy probing support").
That is to say, the new probing paths were never quite correct in this
area.
The existence of the legacy probing support which was deleted in 2019
explains why dsa_dev_to_net_device() returns a conduit with elevated
refcount (because it was supposed to be released during
dsa_remove_dst()). After the removal of the legacy code, the only user
of dsa_dev_to_net_device() calls dev_put(conduit) immediately after this
function returns. This pattern makes no sense today, and can only be
interpreted historically to understand why dev_hold() was there in the
first place.
Change details
--------------
Today we have a better netdev tracking infrastructure which we should
use. Logically netdev_hold() belongs in common code
(dsa_port_parse_cpu(), where dp->conduit is assigned), but there is a
tradeoff to be made with the rtnl_lock() section which would become a
bit too long if we did that - dsa_port_parse_cpu() also calls
request_module(). So we duplicate a bit of logic in order for the
callers of dsa_port_parse_cpu() to be the ones responsible of holding
the conduit reference and releasing it on error. This shortens the
rtnl_lock() section significantly.
In the dsa_switch_probe() error path, dsa_switch_release_ports() will be
called in a number of situations, one being where dsa_port_parse_cpu()
maybe didn't get the chance to run at all (a different port failed
earlier, etc). So we have to test for the conduit being NULL prior to
calling netdev_put().
There have still been so many transformations to the code since the
blamed commits (rename master -> conduit, commit 0650bf52b3 ("net:
dsa: be compatible with masters which unregister on shutdown")), that it
only makes sense to fix the code using the best methods available today
and see how it can be backported to stable later. I suspect the fix
cannot even be backported to kernels which lack dsa_switch_shutdown(),
and I suspect this is also maybe why the long-lived conduit reference
didn't make it into the new DSA probing paths at the time (problems
during shutdown).
Because dsa_dev_to_net_device() has a single call site and has to be
changed anyway, the logic was just absorbed into the non-OF
dsa_port_parse().
Tested on the ocelot/felix switch and on dsa_loop, both on the NXP
LS1028A with CONFIG_DEBUG_KOBJECT_RELEASE=y.
Reported-by: Ma Ke <make24@iscas.ac.cn>
Closes: https://lore.kernel.org/netdev/20251214131204.4684-1-make24@iscas.ac.cn/
Fixes: 83c0afaec7 ("net: dsa: Add new binding implementation")
Fixes: 71e0bbde0d ("net: dsa: Add support for platform data")
Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251215150236.3931670-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
It turns out that HSR offloads are so fine-grained that many DSA
switches can do a small part even though they weren't specifically
designed for the protocols supported by that driver (HSR and PRP).
Specifically NETIF_F_HW_HSR_DUP - it is simple packet duplication on
transmit, towards all (aka 2) ports members of the HSR device.
For many DSA switches, we know how to duplicate a packet, even though we
never typically use that feature. The transmit port mask from the
tagging protocol can have multiple bits set, and the switch should send
the packet once to every port with a bit set from that mask.
Nonetheless, not all tagging protocols are like this, and sometimes the
port is a single numeric value rather than a bit mask. For that reason,
and also because switches can sometimes change tagging protocols for
different ones, we need to make HSR offload helpers opt-in.
For devices that can do nothing else HSR-specific, we introduce
dsa_port_simple_hsr_join() and dsa_port_simple_hsr_leave(). These
functions monitor when two user ports of the same switch are part of the
same HSR device, and when that condition is true, they toggle the
NETIF_F_HW_HSR_DUP feature flag of both net devices.
Normally only dsa_port_simple_hsr_join() and dsa_port_simple_hsr_leave()
are needed. The dsa_port_simple_hsr_validate() helper is just to see
what kind of configuration could be offloadable using the generic
helpers. This is used by switch drivers which are not currently using
the right tagging protocol to offload this HSR ring, but could in
principle offload it after changing the tagger.
Suggested-by: David Yang <mmyangfl@gmail.com>
Cc: "Alvin Šipraga" <alsi@bang-olufsen.dk>
Cc: Chester A. Unal" <chester.a.unal@arinc9.com>
Cc: "Clément Léger" <clement.leger@bootlin.com>
Cc: Daniel Golle <daniel@makrotopia.org>
Cc: DENG Qingfang <dqfext@gmail.com>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Jonas Gorski <jonas.gorski@gmail.com>
Cc: Kurt Kanzenbach <kurt@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: UNGLinuxDriver@microchip.com
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251130131657.65080-6-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Allow devlink_param::get() handlers to report error messages via
extack. This function is called in a few different contexts, but not
all of them will have an valid extack to use.
When devlink_param::get() is called from param_get_doit or
param_get_dumpit contexts, pass the extack through so that drivers can
report errors when retrieving param values. devlink_param::get() is
called from the context of devlink_param_notify(), pass NULL in for
the extack.
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com>
Link: https://patch.msgid.link/20251119025038.651131-2-daniel.zahka@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for legacy Broadcom FCS tags, which are similar to
DSA_TAG_PROTO_BRCM_LEGACY.
BCM5325 and BCM5365 switches require including the original FCS value and
length, as opposed to BCM63xx switches.
Adding the original FCS value and length to DSA_TAG_PROTO_BRCM_LEGACY would
impact performance of BCM63xx switches, so it's better to create a new tag.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250614080000.1884236-3-noltari@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
New timestamping API was introduced in commit 66f7223039 ("net: add
NDOs for configuring hardware timestamping") from kernel v6.6. It is
time to convert DSA to the new API, so that the ndo_eth_ioctl() path can
be removed completely.
Move the ds->ops->port_hwtstamp_get() and ds->ops->port_hwtstamp_set()
calls from dsa_user_ioctl() to dsa_user_hwtstamp_get() and
dsa_user_hwtstamp_set().
Due to the fact that the underlying ifreq type changes to
kernel_hwtstamp_config, the drivers and the Ocelot switchdev front-end,
all hooked up directly or indirectly, must also be converted all at once.
The conversion also updates the comment from dsa_port_supports_hwtstamp(),
which is no longer true because kernel_hwtstamp_config is kernel memory
and does not need copy_to_user(). I've deliberated whether it is
necessary to also update "err != -EOPNOTSUPP" to a more general "!err",
but all drivers now either return 0 or -EOPNOTSUPP.
The existing logic from the ocelot_ioctl() function, to avoid
configuring timestamping if the PHY supports the operation, is obsoleted
by more advanced core logic in dev_set_hwtstamp_phylib().
This is only a partial preparation for proper PHY timestamping support.
None of these switch driver currently sets up PTP traps for PHY
timestamping, so setting dev->see_all_hwtstamp_requests is not yet
necessary and the conversion is relatively trivial.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # felix, sja1105, mv88e6xxx
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20250508095236.887789-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Through code analysis, I realized that the ds->untag_bridge_pvid logic
is contradictory - see the newly added FIXME above the kernel-doc for
dsa_software_untag_vlan_unaware_bridge().
Moreover, for the Felix driver, I need something very similar, but which
is actually _not_ contradictory: untag the bridge PVID on RX, but for
VLAN-aware bridges. The existing logic does it for VLAN-unaware bridges.
Since I don't want to change the functionality of drivers which were
supposedly properly tested with the ds->untag_bridge_pvid flag, I have
introduced a new one: ds->untag_vlan_aware_bridge_pvid, and I have
refactored the DSA reception code into a common path for both flags.
TODO: both flags should be unified under a single ds->software_vlan_untag,
which users of both current flags should set. This is not something that
can be carried out right away. It needs very careful examination of all
drivers which make use of this functionality, since some of them
actually get this wrong in the first place.
For example, commit 9130c2d30c ("net: dsa: microchip: ksz8795: Use
software untagging on CPU port") uses this in a driver which has
ds->configure_vlan_while_not_filtering = true. The latter mechanism has
been known for many years to be broken by design:
https://lore.kernel.org/netdev/CABumfLzJmXDN_W-8Z=p9KyKUVi_HhS7o_poBkeKHS2BkAiyYpw@mail.gmail.com/
and we have the situation of 2 bugs canceling each other. There is no
private VLAN, and the port follows the PVID of the VLAN-unaware bridge.
So, it's kinda ok for that driver to use the ds->untag_bridge_pvid
mechanism, in a broken way.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.
Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some switches like Microchip KSZ variants do not support per port DSCP
priority configuration. Instead there is a global DSCP mapping table.
To handle it, we will accept set/del request to any of user ports to
make global configuration and update dcb app entries for all other
ports.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add DCB support to get/set trust configuration for different packet
priority information sources. Some switch allow to chose different
source of packet priority classification. For example on KSZ switches it
is possible to configure VLAN PCP and/or DSCP sources.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Golle
Vladimir Oltean
Daniel Zahka
Heiner Kallweit
David Yang
Álvaro Fernández Rojas
Russell King (Oracle)
Jakub Kicinski
Kory Maincent
Pawel Dembicki
Oleksij Rempel
Florian Fainelli